Oracle Blog

Thoughts from a Fat Bloke

Thursday Feb 12, 2009

One of the new features of version 2.0 was the ability to run 64-bit guests. However, this initially required a 64-bit host platform to function. For example, to run Windows Server 2008 as a guest on your Windows or Linux PC, you had to upgrade your host system first. This was clearly a "bad thing".

With version 2.1, the VirtualBox team removed this restriction and you can now run 64-bit guests on your 32-bit host. There are still a couple or pre-requisites...

Pre-requisites

your CPU needs to be Intel VT-x or AMD-V capable (for AMD systems this may need to be enabled in the BIOS). We call this Hardware Virtualization.

Configuration

Here's how it is done:

Create a new virtual machine

When specifiying the OS type, select the family and the 64-bit version in the dropdown list box

If you do not see the 64-bit options in the drop-down list then VirtualBox thinks that your machine has not met the pre-requisites above.

Choosing the 64-bit version causes VirtualBox to create a vm which uses the VT-x/AMD-V technology of the CPU, and uses IO APIC too.

That is all there is to it. Continue installing your 64-bit OS into this vm as usual.

Limitation

There is one limitation which is a bit of a pain...

You can run multiple guests at the same time (as you have always been able to do) and you can run a mix of 64-bit and 32-bit guests simultaneously too. But you cannot run 2 vm's, one of which uses VT-x disabled and another, VT-x enabled. Else you will see something like this error message:

To get around this you can either simply save the running guest before resuming the other, or configure all your vm's to use VT-x/AMD-V.